The project I will develop in Dr. R. A. Weinberg's lab focuses on the interaction that exists between the 'positive' and the 'negative' aspects of growth control. Trying to define the link that exists between the Retinoblastoma gene product (pRB) and other proteins that regulate the progression from G0/G1 to S phase of the cell cycle, focussing on the role of cyclins and cdc2/or cdc2-related kinases. After separated walks along the opposite ridge of the river, 'negative and positive scientists' meet at the bridge; the interaction between p107/pRB and cyclins/cdc2 family is the "Golden gate" and Dr. R. A. Weinberg's lab has definitely set up its camp on an island, just where the main pier of the bridge takes place. To continue with allergies I am now on the ridge of the positive regulation, working in the lab of Dr. J. Pouyssegur that focuses on various aspects of the growth factor (GF) activation in fibroblasts; GF-receptors such as thrombin receptor, GF- activated kinases such as MAP kinase or S6 kinase and GF-activated targets such as the Na+/H+ antiporter. The different subjects developed in Dr. R> A. Weinberg's lab are the perfect extension to what I have worked with in Nice; members of Weinberg's lab are expert in other 'positive' aspects of growth such as the Ras-complex but also in 'negative' aspects including TGFbeta receptors and Retinoblastoma gene product.